A major portion of the commerce in the industrialized world involves the shipment and storage of goods. A large majority of these goods are shipped by trucks, especially of the van or semi-trailer type, which have open rear doors. In order to load and unload goods to and from such trucks, they are commonly backed against a doorway opening constructed in a warehouse or other building to form a loading dock. It is common and desirable to provide a dock seal which is mounted around the opening which forms a loading dock. The dock seal provides a weather barrier so that the goods may be protected, the workers will not be exposed to weather and the heated or air conditioned air within the building will not be lost.
A substantial variety of such dock seals of various constructions have been proposed in the past for providing a suitable seal. Recently, the adoption of newer, wider body truck trailers has meant that a dock seal must be capable of sealing trucks of different widths. As a result, the L-shaped seal, which I invented and which is illustrated in my U.S. Pat. No. 4,213,279, has become popular because of its sealing effectiveness in dealing with different sized truck bodies.
I have discovered, however, that a problem exists when the L-shaped seal is used with trucks of the type having two hinged doors each closing half of the rear opening of the trailer. These doors pivot from their closed position around to a full opened position at the sides of the trailer. The problem is that a hinge gap exists between the door and the trailer body when the door is open. The L-shaped seal effectively wipes and seals the sides of the truck, as described in my patent, by wiping against the outwardly facing interior side of the doors, but does not seal this hinge gap.
In the past when standard trailers of uniform width were in use, the problem was non-existent when the old compression seals were used against which the truck backs to compress the seal against the wall of the building. Although a compression seal avoids the problem for a uniform width trailer, dock openings are now constructed wider in order to accomodate the wider body trucks. A compression type dock seal would need to extend inwardly from the sides of the opening to accomodate the narrower trucks. As a result, a compression seal which could accomodate both wide and narrow trucks would block a portion of the newer, wider dock openings.
It is also important that a dock seal which seals the hinge gap of either wide or narrow trucks never extends significantly inwardly of the truck opening. If it does, in use it will be occasionally struck and torn by loading and unloading equipment, and will therefore be in need of frequent, periodic repair.
There is therefore a need for a structure for sealing the hinge gap of truck doors which will provide an effective seal for truck bodies of wide or standard widths, yet which will not be subject to damage in the ordinary course of use of the loading dock. It is a further object of the invention to provide a dock seal with a hinge gap sealing structure which will operate effectively for multi-width truck bodies even though the truck may not be backed squarely against the dock.